Monitoring Phytoremediation Processes Using the Green Fluorescent Protein

65521 To optimize the removal of heavy metal contaminants from soil and water using phytoremediation, field-scale process monitoring will be required. Plant biosensors that indicate the presence of heavy metals could offer high spatial resolution, stand-off reporting, ready scaling to large treatment areas, and continuous operation. This project will develop such plant biosensors, by utilizing the Green Fluorescent Protein (GFP), which, when expressed in plant cells, yields a bright green fluorescence under UV light. By transforming plants with the GFP gene fused to a metal responsive promoter (MRP) element, plants can be developed that express GFP only in the presence of certain metal ions. Such plants could then be used to monitor the concentration of pollutant metal ions. In Phase I, the library preparation and sequencing of the putative MRP from Indian mustard was completed. Subsequently, the putative MRP was prepared and cloned into a GFP gene. In Phase II, Arabidopsis will be transformed using the MRP-GFP construct, and a homozygous seed will be selected. GFP expression in transgenic Arabidopsis containing the MRP-GFP construct will be characterized, then Indian mustard will be transformed with the construct. In growth chamber studies, transgenic Indian mustard seedlings will be analyzed for their ability to detect various metal ions in polluted waters. A field demonstration of the ability of transgenic Indian mustard seedlings to detect metal ions in leachate will be conducted. Commercial Applications and Other Benefits as described by the awardee: The plant biosensor should make the commercial cleanup of contaminated soil and water more competitive by allowing precise control of the phytoremediation process and reducing operating costs. Other environmental detection and monitoring applications include water treatment systems to maximize metal ion removal and monitor the purity of effluent water.